@keyframes y-animaton{
    from {
        opacity: 0.2;
    }
    to {
        opacity: 1;
    }
}

div {
    animation-name: y-animaton;
    animation-duration: 10s;
    border: 1px solid red;
    background-color: aqua;
    margin: 20px;
    padding: 20px;
    border-radius: 40px;
}

div:hover {
    scale: 1.1;
    background-color: aquamarine;
}
